The 18-year-old told Press Association Sport: "Martin Jol is a calm manager.
"He knows exactly what he is doing.
"He gives the younger players an opportunity as well, like Alex Kacaniklic was on the bench against Sunderland.
"He is a really good coach that wants to help players.
"If you are on the table for food, the younger players sit with [the older ones].
"Being with the senior players is a great plus.
"You see in training how they score goals and you are always thinking 'how did they do this?', 'how can I do this well?'
"I will always talk to them and they help you. They are great boys."
The Swiss midfielder has made six appearances for the Cottagers this season, mainly as a substitute.
"It has been quite a good season so far," Frei said.
"I started against Chelsea for 120 minutes and also the Europa League games as well.
"My first game was in the Faroe Islands. There were not too many people there but it was still good.
"For a 17-year-old to make his debut was great, although I was more nervous against Chelsea than the other teams.
"I think for every kid it is a dream to play in the Premier League [against the biggest clubs].
"To play against a team like Chelsea, that was special."